#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL a[maxn];
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL n;cin>>n;
  LL gcd=0;
  for(LL i=1;i<=n;i++){
    cin>>a[i];gcd=__gcd(gcd,a[i]);
  }
  if(gcd>1){
    cout<<"YES"<<"\n";
    cout<<"0"<<"\n";
  }
  else if(gcd==1){
    for(LL i=1;i<=n;i++){
       if(a[i]&1) a[i]=1;
       else if(a[i]%2==0) a[i]=0;
    }
    LL ans=0;
    for(LL i=1;i<n;i++){
        if(a[i]==1&&a[i+1]==1) ans+=1,a[i]=0,a[i+1]=0;
    }
    for(LL i=1;i<n;i++){
        if(a[i]==1&&a[i+1]==0) a[i]=0,a[i+1]=0,ans+=2;
        else if(a[i]==0&&a[i+1]==1) a[i]=0,a[i+1]=0,ans+=2;
    }
    cout<<"YES"<<"\n";
    cout<<ans<<"\n";
  }
return 0;
}
